Chiral Symmetry breaking in Three Dimensional QED

TL;DR

This paper uses lattice simulations to investigate whether chiral symmetry is spontaneously broken in three-dimensional QED, with implications for understanding phases of high-temperature cuprate superconductors.

Contribution

It provides the first strong numerical evidence that QED$_3$ remains chirally symmetric for $N_f \,\geq\, 1.5$, clarifying the phase structure relevant to high-$T_c$ materials.

Findings

QED$_3$ is chirally symmetric for $N_f \geq 1.5$

A pseudogap phase exists between superconducting and antiferromagnetic phases

Lattice simulations support the phase diagram of high-$T_c$ cuprates

Abstract

Over the past few years three dimensional Quantum Electrodynamics (QED$_3$) has attracted a lot of attention, because it may be an effective theory for the underdoped and non-superconducting region of the phase diagram of high $T_c$ cuprate compounds. We present results from lattice simulations of the non-compact version of the theory in order to address the issue of whether chiral symmetry is spontaneously broken when the number of fermion flavours $N_f$ is less than a critical value $N_{fc}$. Our results provide strong evidence that QED$_3$ is chirally symmetric for $N_f \geq 1.5$, implying that a pseudogap phase separates the superconducting phase from the antiferromagnetic phase.